A COMPARISON OF SEGMENT FEATURES IN THE SPEECH CHAIN OF THREE DEAF-BORN BOYS WITH THOSE OF THREE NORMAL-HEARING BOYS REVEALS THAT THE DEAF-BORN HAVE SPEECH PROBLEMS ASSOCIATED WITH A LACK OF SYNCHRONY BETWEEN ARTICULATION AND PHONATION. IN ORDER TO DETERMINE THE DIFFERENCES BETWEEN THE TWO GROUPS (BOTH REPEATING THE SAME SWEDISH SENTENCES), A SPECTROGRAM SEGMENTATION METHOD WAS USED, ANALYZING THE MANNER OF PRODUCTION AND CORRESPONDING ACOUSTIC CORRELATES OF THE SOURCE FEATURES AND RESONATOR FEATURES. SPECTROGRAMS REVEALED THAT THE DEAF BOYS' SPEECH DEVIATED FROM NORMAL PATTERNS IN VARIOUS WAYS, PARTICULARLY IN AN ERRATIC TRANSITION IN SOME PARTS OF THE VOWEL. IN ADDITION, THE ARTICULATION WAS NOT ALWAYS UNDER CONTROL, AND THE DEAF BOYS HAD DIFFICULTY WITH FRICATIVE ASPIRATION. THE SECOND PART OF THIS TWO-PART STUDY DESCRIBES A SPECTROGRAM SEGMENTATION TECHNIQUE IN WHICH SEGMENT BOUNDARIES COINCIDE WITH A CHANGE IN THE FEATURE COMPOSITION. AN EARLIER MODEL WAS LIMITED BY THE FACT THAT SLIGHT SHIFTS IN THE TIMING OF FEATURES CAUSED NEW SEGMENTS TO ARISE. ALSO, TIME DURATION OF SEGMENTS WAS NOT INDICATED. THE REPRESENTATION OF FEATURES AS A FUNCTION OF TIME WAS CONSIDERED MORE ADVANTAGEOUS, AND THEREFORE, A COMPARISON OF THE DURATION OF PHONEMES BETWEEN NORMAL HEARING AND DEAF SUBJECTS WAS CARRIED OUT. THE RESULTS SHOW A MUCH LOWER RATE OF SPEAKING FOR DEAF SUBJECTS. THIS DOCUMENT WAS PUBLISHED IN QUARTERLY PROGRESS AND STATUS REPORTS, OCTOBER 1965 AND JANUARY 1966, BY THE SPEECH TRANSMISSION LABORATORY, ROYAL INSTITUTE OF TECHNOLOGY, STOCKHOLM. (FB)